Polyester fiberfill (sometimes referred to as fiberfilling material) is used commercially as filling material for many stuffed articles, including pillows and other home furnishings and bedding articles, such as comforters, quilts and sleeping bags, and also in, for example, filled apparel, such as anoraks.
Marcus disclosed in U.S. Pat. Nos. 4,618,531 and 4,783,364 and in EP 203,469 using such polyester filling material randomly entangled together in the form of refluffable fiberballs, and Marcus disclosed therein an air-tumbling process for making such fiberballs from feed fiber of spiral crimp (more correctly perhaps termed helical configuration) such as can be made by air-jet quenching or by spinning fibers from bicomponent polymer systems. Such an air-tumbling process as Marcus described has given excellent results, but has limitations, for instance in the type of feed fiber that should be used and in productivity, being a comparatively slow batch process and involving use of a revolving drum whose capacity has been a limiting factor. Other processes that have been used and developed have involved modifying carding machines (cards) to produce lofty randomly-entangled fiberballs instead of parallelized (carded) webs. Snyder et al in U.S. Pat. No. 5,218,740, disclosed examples of such modified cards, that may include modified roller-type cards, modified flat top cards and other modified types of cards, and how to process feed fiber that may have spiral crimp, or have been mechanically crimped as disclosed for example in Halm et al. U.S. Pat. Nos. 5,112,684, 5,238,512 and allowed application Ser. No. 08/073,294 now U.S. Pat. No. 5,338,500 . Such processes overcome some of the limitations of Marcus' air-tumbling process, but it has still been desirable to improve productivity.
In addition to refluffable fiberballs (variously called by other terms, commercially, such as "clusters" and "puffs" for example), Marcus also described making randomly-entangled fiberballs including also binder fiber and processes that used such fiberballs as intermediates for making molded products, such as cushions and mattress cores, for examples, in U.S. Pat. Nos. 4,794,038, 4,940,502, 5,169,580, and allowed application Ser. No. 08/010,215 now U.S. Pat. No. 5,344,707. For simplicity, when considering fiberballs made from blends including binder fiber, the other fiber (other than the binder fiber) is sometimes termed the "load-bearing fiber" in contrast to the binder material. In practice, preferred binder fibers are often bicomponent fibers, only part of which is binder material that melts or softens, while the remainder becomes load-bearing after activation of the binder material. Snyder et al and Halm et al also disclosed like fiberballs, processes and molded products in their aforementioned patents.
All of the patents mentioned above are incorporated herein by reference.
A problem that has been solved by the present invention is how to make fiberballs for filling purposes and as intermediates for making molded products at greater productivity than has been suggested in the art.